Taking precautions through genetic testing

Joan Horst of Harrisonburg wasn’t completely surprised to be diagnosed with thyroid cancer. Her father had died of an incurable form of thyroid cancer three decades earlier, and her father’s mother and two sisters had their thyroid glands removed because of benign growths. One of her maternal aunts survived thyroid cancer as well.

Joan, 68, beat thyroid cancer, but she was later diagnosed with breast cancer. It was caught early, so she had it treated with radiation and then hormone therapy.

Because her maternal grandmother had a mastectomy due to breast cancer, Joan was eager to learn more about her family’s cancer risks at the urging of breast surgeon Dr. Heidi Rafferty of Sentara RMH Medical Center breast care program and medical director for the Funkhouser Women’s Center. She recommended genetic counseling for Joan to explore possible explanations for the cancerous and noncancerous conditions that had affected so many of her relatives.

“Knowledge is power, and when people have information about their genetic vulnerabilities, they have the power to do or not do something about it,” says Dr. Rafferty. “Genetic testing is not appropriate for everyone. But I’ve seen lives saved and certainly lives extended because an appropriate person, or a relative of that person, was tested and found to be a carrier, and then that person or the person’s relative had planned preventive surgery and a small cancer was found.”

Unraveling Family Mysteries

Joan met with Martha Thomas, MS, CGC, a certified genetic counselor who sees patients at the Sentara RMH Funkhouser Women’s Center and the Sentara RMH Hahn Cancer Center. The counselor suspected that Joan had Cowden syndrome, an inherited condition caused by a mutation in the PTEN gene.

Although that didn’t turn out to be the case, Martha doesn’t rule out a genetic cause for the cancer and benign growths that are prevalent in her family.

“A negative genetic test result doesn’t mean a decreased risk of cancer—it could simply mean that we don’t know what to look for in a genetic sense,” says Thomas. “We still have to take Joan’s family and medical histories into consideration. And based on that history, I’d recommend close monitoring and early screenings for her and her relatives, no matter what the results of her test reveal.”